The present disclosure is directed to a co-formed element having a core structure formed from a high thermal conductivity ceramic matrix composite material and a low thermal conductivity layer.
Gas turbine engines operate over a large temperature range. The internal flowpath is exposed to high gas pressures, velocities and temperature variations. Additionally, gas turbine engines are capable of accelerating and decelerating very quickly. The net result is flowpath exposed parts, such as blades, vanes, and shrouds can see large transient heat loads. High thermal conductivity (hi-K) ceramic matrix composites (CMC) are required to quickly dissipate the transient thermal gradients, and reduce the transient thermal stresses.
Parts made from CMC materials offer the ability to operate at temperatures above the melting temperature of their metallic counterparts. For hi-K CMC's, heat conduction into a metallic attachment part could overheat the metal in the attachment part. In these situations, the metal attachment part may have to be cooled, even though the CMC part does not require cooling. Adding cooling flow could create damaging local thermal gradients in the CMC part.